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The sheepshead minnow as an in vivo model for endocrine disruption in marine teleosts: A partial life‐cycle test with 17α‐ethynylestradiol
Author(s) -
Zillioux Edward J.,
Johnson Isabel C.,
Kiparissis Yiannis,
Metcalfe Chris D.,
Wheat Jeff V.,
Ward Scott G.,
Liu Hui
Publication year - 2001
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620200915
Subject(s) - biology , toxicant , vitellogenin , minnow , hatching , sexual maturity , andrology , endocrine disruptor , endocrine system , reproduction , toxicity , toxicology , physiology , zoology , fish <actinopterygii> , medicine , endocrinology , ecology , fishery , hormone
The sheepshead minnow ( Cyprinodon variegatus Lacépède), an estuarine fish species, was exposed to 17α‐ethynyl‐estradiol (EE2) at nominal test concentrations of 0.2, 2, 20, 200, 400, 800, 1,600, and 3,200 ng/L. Fish were exposed for up to 59 d, from subadult stages to sexual maturity, under flow‐through conditions. The exposure period was followed by an evaluation of reproductive success and survival of progeny. The reproductive success of exposed sheepshead minnows, as determined from data on egg production from two subsequent spawning trials, was reduced in fish exposed to 200 ng/L EE2 and, in one spawning trial, in the 20‐ng/L treatment. Hatching success was reduced in the progeny of fish exposed to 200 ng/L EE2, but survival was good among fry that successfully hatched. Histological examination indicated generalized edema, damage to gill epithelia, hepatic toxicity, fibrosis of the testis, and evidence of sex reversal, including testes–ova and spermatagonia‐like cells in ovaries. The maximum acceptable toxicant concentration (MATC) for gonadal development in males was within the normal range of EE2 concentrations in sewage treatment plant effluents. The exposure regimen and choice of test organism, combined with histological examination, allowed independent evaluation of ecologically significant acute, reproductive and estrogenic endpoints. Estrogen receptor–mediated effects occurred at concentrations where reproductive effects were measurable under standard reproduction assays. The sheepshead minnow appears to be a sensitive in vivo model for partial life‐cycle testing of compounds that have the potential to disrupt the endocrine system as well as reproduction in estuarine and coastal marine fish species.